The present invention relates to the production of multi-layer ceramic laminates for electronics applications, and more particularly to a process and apparatus for preparing a release layer for releasing green ceramic laminates from a lamination fixture.
In the production of multi-layer ceramic parts such as multi-layer ceramic capacitors, a plurality of ceramic green sheets serve as platforms upon which chips, passive components, protective lids, and thermal enhancement hardware are attached. A plurality of ceramic green sheets, each patterned with conductive circuit layers interconnected by conductive vias, are precision stacked and compression laminated to each other. The green (pre-sintered) multi-layer ceramic laminate is then removed from the lamination plate for molding, cutting, and firing to obtain individual multi-layer ceramic sintered bodies. During this process, the green multi-layer ceramic laminate must be removed from the lamination plate without adverse consequences to the laminate such as damage caused by the laminate sticking to the lamination plate. One current process for facilitating removal of the ceramic laminate from the lamination plate comprises cutting a non-sticky material, such as polyethylene terephthalate film, to the desired dimensions, and placing the pre-cut film between the lamination plate and the stacked layers of ceramic green sheets prior to lamination. Such an approach is labor intensive, and as such, increases the production cost of the final product.
U.S. Pat. No. 4,756,959 to Ito et al. discloses a sheet for use in firing ceramic faced base plates comprising a combustible sheet such as pulp paper and a coating layer comprising a high melting point powder such as ceramic powder and a powder of carbon disposed on the combustible sheet. The sheet is cut to a desired size and placed between ceramic faced base plates which are stacked in a vertical direction during firing. The combustible sheet is incinerated during firing, leaving the powder of ceramics remaining between the ceramic faced based plates. This process is also time-consuming and expensive.
There is a need in the art for an improved process and apparatus for forming a release layer and facilitating release of green ceramic laminates from a lamination fixture after completion of the lamination process.